Duties and Destinies
by Aish Sheva
Summary: The final battle, with a twist. When Percy is killed, all is lost...or is it? What if Percy's not the prophecy child after all?


**WARNING:** Contains some of the most convoluted logic you'll ever experience, a good dose of aliquot sums, and just a sort of bizarre overall plot.

The** aliquot divisors** of a number are all of its divisors except the number itself. The **aliquot sum** is the sum of the aliquot divisors so, for example, the aliquot divisors of 12 are 1, 2, 3, 4, and 6 and it's aliquot sum is 16.

Thanks so much to RaechelleMarie, sistergrimm2, GreekGeek7, Ellen 26, and anyone else who critiqued and praised this or even just offered to do so. :)

* * *

The battle rages all around him. Gods, monsters, and half-bloods, clashing swords. He notices none of it. His mind is focused solely on reaching the smirking man right in the thick of things, smiting those around him with a single wave of his hand. The boy glances around. He knows that if he doesn't reach Kronos, all will be lost. They are hopelessly outnumbered, and this is their last chance. The choice foretold hasn't come yet, and he is starting to wonder if it ever will.

_Just keep on going..._something reminds him. Mouth pressed into a thin line, he slashes a path through, leaving a trail of destruction behind.

With grim determination, he focuses on nothing but cutting down the monsters in front of him. Riptide swinging wildly, shield held out to deflect any incoming blows, he slowly but surely gets closer.

He is almost there when it happens. A Cyclops approaches him from behind, draws his sword, and stabs him in the back just once. It does the trick. The boy falls to the ground, mortally wounded. The Cyclops doesn't even look to see who his victim was, simply continues onward, laughing.

He lies there on the ground, completely helpless. He feels death slowly approaching, and knows that there is nothing he can do about it. His vision blurs, and for a second he thinks he sees Nico, hovering at the edge of his vision.

And then it's not a vision, and Nico really _is _there, and Annabeth is with him, tears streaming down her face. He smiles weakly, thinking that he's only see Annabeth cry once before this. She stuffs an ambrosia square into his mouth before he can tell her it's no use. The wound is too deep. He knows that he will die soon, and he is not afraid.

He looks at up Annabeth and tells her not to cry, it will be fine. A lie, and they both know it. Then, he turns his head so that his line of sight is directed at Nico. He meets his gaze, and then inclines his head slightly, telling him to do what he needs to do. Then Percy Jackson inhales one last time-a great, shuddering, gasp-and closes his eyes for eternity, an expression of serenity blossoming on his face. At last, the weight of the prophecy is off him.

* * *

Nico knows the instant his cousin is stabbed. The buzzing that has been reverberating in his ears throughout the entire battle suddenly intensifies a hundredfold. He finishes off the monster, anger fueling him on, and then locates Annabeth. He helps her defeat a Laistrygonian giant, and then pulls her toward where he knows Percy is lying.

When they get there, Annabeth starts to cry. Nico doesn't blame her. He is shocked by how easily Percy's death was brought about. One hit, and he was gone.

There is no hope for them now.

* * *

Annabeth stands over Percy, next to Nico. She can't believe that Percy is dead-she _won't _believe it. But the evidence doesn't lie, and there is Percy's body lying in front of them.

Then, something snaps. This is no time for tears. It is a time for action. She grabs Nico, spins him around so that they're eye to eye.

"Nico. The soul exchange."

Nico stares at her. The memory of a sandpaper dry voice floats into his memory. _Yes, master...the soul exchange._

"What about it?"

"Is it too late? Because I know how we can stop this, I know how to make it work. We have to hurry, hurry, I think it will work, I know the prophecy inside and out and this is a loophole..." The words spill out faster and faster now. Nico's head spins trying to keep up.

"What am I supposed to do?" he queries.

"Trade Percy's soul for Bianca's."

"What?!" Nico is stunned.

Annabeth's eyes take on a slightly maniacal quality.

"DO IT," she hisses. "I hope it's not too late."

Nico bites his lip. "Are you sure?"

"Yes!" she shouts. "Just do it!"

Nico focuses for a moment. He closes his eyes and instead looks with his mind across the battlefield. There is Thanatos, marching toward them. As he stoops low over Percy's body to collect the soul, Nico sends out a silent question in Ancient Greek.

_Will you take me with you?_

Thanatos doesn't question, simply walks over to Nico when he is done with Percy, and tosses him a long, snake-like rope made of what looks like fire.

Nico holds on to one end and closes his eyes. There is a rush of noise, he sees a blur of colors through his scrunched up eyelids, and then suddenly he is in Hades's throne room.

While the other gods were fighting, Hades remained behind. Death, after all, waits for no one and nothing.

Nico clears his throat. "Father." He speaks in the language of the Underworld-paper thin rustles of sound and quiet murmurings. It is as natural for him as breathing.

"Son. You have come for the soul exchange." Hades wastes no time, instantly sensing Nico's motives.

"Yes."

Hades says nothing, merely looks at him with those cold, deep pits of blackness he has for eyes.

"In exchange for the soul of Bianca di Angelo, daughter of Hades, I give you the soul of Perseus Jackson, son of Poseidon. He has cheated death on several occasions: when he used the pearls to escape the Underworld, when he rescued his mother, when he escaped the Cyclopes Polyphemus, when he was cured of the scorpion's poison, when he...when he..." Nico paused, knowing he is forgetting something but not sure what.

Hades nods. "Are you sure?"

Nico draws in a shaky breath. "Yes." He closes his eyes again, as, in a flash of golden light, Bianca appears in front of him.

She looks around, confused. "Wh-what's happening?"

Hades doesn't answer, but continues in his speech. "You have traded the soul of Perseus Jackson for Bianca di Angelo."

Nico nods.

"Be warned. If she remains in the Underworld for any longer, the exchange shall be reversed."

Nico's eyes widen, and he grabs Bianca's hand. "Let's go," he urges.

Still confused, she follows.

"Don't look back," he whispers, and she nods.

It seems like an eternity until they are above ground again, but in reality hardly any time has passed at all. Kronos has no hold in the Underworld.

Annabeth is fighting off a monster, glancing around between swings, waiting for them. When she sees Bianca, she nearly drops her sword, but manages to continue battling the monster under it is finished. As soon as it crumbles into dust, she stumbles over the brother and sister, standing side by side.

"You did it," Annabeth gasps. She is a mess, hair matted with blood and sweat.

"Yes," Nico mumbles, feeling guilty.

Meanwhile, Bianca is looking around with a mixture of wonder and horror. "What's _happening?_" she asks quietly.

"The battle," Annabeth rushes to explain. "Kronos attacked...Percy was supposed to turn sixteen today and be able to defeat him..." She swipes at her eyes. "But then I realized something. What if...Percy was never the prophecy child? What if-" She looks Bianca straight in the eye. "What if it was _you_?"

Bianca looks stunned. "I'm only twelve."

"Yes, I know. But sixteen is the aliquot sum of twelve!"

Nico joins Bianca in confusion. "What?"

"Sixteen is the first number to be the aliquot sum of a lesser number: twelve. I'm not going to explain what that means right now, but the bottom line is that I think this will work."

She doesn't wait for an answer, foraging straight ahead.

"I thought about it. It's a loophole in the prophecy. The Oracle never said that the prophecy kid had to be sixteen years old, just that they would make the decision on their sixteenth birthday. Since sixteen is the aliquot sum of twelve, and therefore we can say that sixteen is equal to twelve...it's you, Bianca."

Nico stares at her. "That is the most twisted logic I've ever heard."

Bianca looks at Nico, then at Annabeth. "Maybe....just maybe...that will work..."

Annabeth nods. "A choice. The prophecy said that there would be a choice that would lead to either the downfall or the victory of Olympus."

Bianca lowers her head. "Okay."

Annabeth nods. "Now, if my theory is correct, it will find _you. _Bianca-stay out of the way! You can't get hurt. Nico-come with me, and help me fight."

The two siblings hug each other, and then Nico runs back into the fight with Annabeth.

* * *

Bianca can see that things don't look good. Their side is hopelessly outnumbered, more then ten to one. She hides behind a tree, feeling helpless. She has no weapon, no training, and no idea of what she's supposed to do.

Time drags on. Bianca sees death all around her, hears a constant buzzing in her ears. Annabeth and Nico never do come back, and she starts to fear the worst. Her legs are shaking, and she has to sit down.

Suddenly, the noise changes. The buzzing slowly shifts to a high pitched whine, growing louder and louder by the second. Bianca claps her hands over her ears, but it's no use. The sound is in her head. She stands up and peeks out from behind her hiding spot, swiveling her head to locate the noise.

That's when she sees it. Off in the distance, but growing closer every second, something is coming. Bianca can't see what it is yet, but something tells her that it is very, very bad. The noise reminds her of when she saw a homeless man in the street, slowly dying, except it's amplified times two. She thinks hard, but she's not sure what it could be. Annabeth and her brother have left her with no information on what she's supposed to do, no information on who she's supposed to attack, nothing. But then she remembers something, a faint memory, of one spirit whispering words to another...

Being the daughter of Hades has its advantages in the afterlife. Bianca has heard things that other souls would not have, bits and pieces of information. One such snippet was from a soul...she thinks hard, trying to remember who's. A boy named Lee Fletcher, that was it! He had been talking about a war...and an evil Titan lord named Kronos. Bianca struggles to recall what she knows about him from Greek mythology. He was the Lord of Time, she thinks. Very, very powerful. And then, oh, gods, how will I be able to defeat him?

She closes her eyes, but doesn't bother to pray. The gods are either out here, fighting with them, or working to restrain Typhon. This is something she'll have to do on her own.

A sense of calm fills her. As the noise-and therefore Kronos-draws closer, she realizes that she knows what she has to do. It's almost as if she's done it before...

It's sudden, too sudden for the girl to react. One minute Kronos isn't there, and the next he is, scythe in hand, smirk on face. He looks at her with cold, merciless eyes.

"Who are _you_?" he sneers. A second later, he answers his own question. "Ah. Bianca di Angelo, daughter of Hades. The back-up prophecy child, the replacement." She leans back with a shudder at the spite in his voice.

"Tell me, child, is this what you want? To have the weight of the world on your shoulders?" He pauses, long enough for her to digest the thought, but not long enough to reply. "Come and join me. The gods have betrayed you. You were killed, and none of them did anything to stop it. Join me. You will gain unlimited power, and Olympus will fall at your feet. And when I rule the new world, you shall rule with me as my queen."

Bianca's fatal flaw isn't power, and it never has been. She's not tempted by his offer. Instead, all her thoughts are focused on the buzzing sound coming from him.

"Think," he cajoles her. "Free of your little brother...immortal..."

She ignores him, willing her ears to block out the sound.

Then, Kronos realizes something that makes him snap to attention. "You are not sixteen, are you? No, you are twelve...so how is that the prophecy as fallen on you?" He eyes her questioningly and one hand reaches toward the curved scythe at his side.

Bianca can see he will be held back no longer and knows she was lucky to get as long a delay as that.

But before Kronos starts his death advance, he says once more: "Is this what you want?"

Then he moves forward.

Bianca dances backward, scrambling behind a tree. "No," she replies, drawing on courage she never knew she had. "But it's my destiny."

Some part of her has known for a long, long time that the prophecy-even if it falls to her only through a loophole-is and has always been her duty. And she is ready to face it.

Bianca di Angelo is ready to save the world.

* * *

Please review. It's the only payment a fanfiction author gets. ^_^ Flames are accepted, and CC is greatly appreciated.

A final note: this is the cut version. The original included a battle scene between Bianca and Kronos. If you'd like me to post the cut material, please mention it in your review.

Have a nice day!

~Aish Sheva


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